Why do Christians and Muslims believe in the concept of Satan when it comes from Zoroastrianism? Jews don’t believe in Satan as evil. And Jesus was a Jew – so he would never have spoken of Satan as evil.

In 538 BC the Jews returned from exile to their homeland, now under the rule of the Persians. The Hebrews were heavily influenced by the Persian beliefs, in particular Zoroastrianism, and it is at this time that we see a shift in their beliefs.

Specifically, the adoption of the Persian view of Satan.

The Zoroastrian God, Ahura Mazda, was opposed by the evil entity Angra Mainyu, the Destructive Element. Angra Mainyu (also known as Ahriman) became the ultimate embodiment of evil. He was constantly attempting to destroy the world of truth and to harm men and beasts. In chapter 100 of Book of the Arda Viraf, titled ‘Ahriman’, the narrator saw Angra Mainyu, the “Evil spirit, … whose religion is evil [and] who ever ridiculed and mocked the wicked in hell.” Angra Mainyu lived in a world of darkness with the demons (daevas) as their ruler or leader (Vendidad 19.1, 43-44).

Most noteworthy is Angra Mainyu’s ability to change his appearance to that of a lizard, a snake or an innocent looking youth. So disguised, he wages his war against Ahura Mazda as he attempts to destroy all that is good and to lure man into the world of darkness and destruction.

For Zoroastrians, the mortal world was a reflection of the cosmic struggle between these two divine entities: The Supreme God Ahura Mazda and his arch-nemesis, Angra Mainyu. Man was charged with choosing between these two principles, good and evil.

Ultimately, at the end of the world a Savior (Saoshyant – also known as “the shepherd to the poor”) will come, and he will defeat Angra Mainyu. All mankind, wicked and righteous alike, would be resurrected to an immortal body, and the final judgment would come wherein all would be held accountable for their choices. The world would be cleansed and changed by fire and molten rock and the righteous would reside in Light and Truth while the wicked would be purged through fire until they were washed clean of their wickedness. Angra Mainyu and his minions would ultimately be destroyed.

It should be no surprise that during the post-exilic period we find that the Hebrew’s view of God changed from a jealous, vengeful God who was the source of both good and evil, to a God of love and righteousness (Ahura Mazda), and that an evil figure responsible for sin and suffering, such as Angra Mainyu, would then emerge.

And so the Hebrew ha-satan, the Accuser, evolved into Satan, the Devil.

A number of apocryphal texts that emerged between the first century BC and the first century AD relate the oral tradition that had sprung up regarding the evil figure of Satan. These texts describe Satan as a fallen angel who was cast out of heaven because of his pride, refusing to be subservient to Adam. Because of his fall from grace he sought to first destroy Adam and then mankind in general.

Through these accounts we see that by the Inter-testamental period Satan, the fallen angel, had become the serpent in the Genesis story (Genesis never states that the serpent was the Devil or Satan, the serpent is simply a serpent.) However, the apocryphal text The Life of Adam and Eve claims that Satan possessed the serpent.

“Then he [Satan] went and summoned the serpent and said to him, ‘Arise, come to me so that I may enter into you and speak through your mouth as much as I will need say’. At that time the serpent became a lyre for him…” (The Life of Adam and Eve 17.2).

Additionally, the apocryphal Book of Wisdom declared, “But by the envy of the devil, death entered the world, and they who are in his possession experience it” (Book of Wisdom 2:24).

And so we see a new dualistic depiction of Satan emerge. He was prideful and cast out of heaven to become a demon. He was pure evil and led the fallen angels in a war against God, trying to destroy mankind through deceit. He brought death to the world and became synonymous with the serpent of Genesis. He has the power to possess animals and mankind. He can appear as an angel, a man or a serpent.

In essence, he acquired the characteristics of Angra Mainyu.

During the Inter-testamental period Satan went by numerous names. He was Mastemah (Enmity) in the Book of Jubilees, Belial in the Testament of the Twelve Patriarchs, and the Angel of Darkness in the Dead Sea Scrolls.

But it is in the New Testament that he received his most lasting names. He is the Devil (Matthew 4:1-11), Satan (Luke 22:3, 31), the Wicked One (Matthew 13:19; Mark 4:15), the Father of Lies (John 8:44), the author of all evil (Luke 10:19), the Lord of Death (Hebrews 2:14), the Great Dragon (Revelation 12:9), and the Ruler of Demons (Matthew 9:34).

In contrast to the Old Testament, belief that God was the source of good and evil as well as suffering changed. In the New Testament it was Satan who caused pain and affliction (Luke 13:16), not as a result of man’s moral failings and sin as was believed anciently, but precisely because man was righteous Satan sought to harm him and make him suffer.

The New Testament also echoed Old Testament and Apocryphal traditions. Using terminology very similar to Isaiah, Jesus was said to have beheld Satan fall as lightning from heaven because of his rebellion against God (Luke 18:10). The book of Revelation paraphrases the Apocryphal accounts of Satan’s fall:

“And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him” (Revelation 12:9).

And in Jude we have a reference to the fall of the angels in unmistakable Zoroastrian terminology referring to their dwelling as Darkness and the great Day of Judgment.

“And the angels which kept not their first estate, but left their own habitation, he hath reserved in everlasting chains under darkness unto the judgment of the great day “(Jude 1:6).

But the evolution of Satan did not end with the writings of the New Testament. Over the next millennia Satan continued to acquire familiar folkloric attributes and characteristics as Christians incorporated various pagan beliefs and demonized pagan gods. These depictions, derived from numerous ancient sources and legends, bled into Satanic lore from other cultures.